Field of the Invention
The present invention relates to a driving device for a liquid ejection head.
Description of the Related Art
There has been known a liquid ejection printing apparatus configured to eject liquid such as ink to perform printing. The liquid ejection printing apparatus includes a liquid ejection head configured to eject liquid. The liquid ejection head may include ejection orifices configured to eject liquid, pressure chambers communicating with the respective ejection orifices, liquid supply paths configured to supply the liquid to the respective pressure chambers, and energy-generating elements arranged for the respective ejection orifices. The energy-generating element may be made of a piezoelectric material such as lead zirconate titanate (PZT) and configured to change a volume of the pressure chamber to supply and eject liquid. When the volume of the pressure chamber is contracted, the liquid in the pressure chamber is ejected from the ejection orifice as droplets. When the volume of the pressure chamber is expanded, the liquid is supplied from the liquid supply path to the pressure chamber.
In the field of the printing apparatus, in recent years, there has been a demand for higher image quality and higher speed. Thus, the liquid ejection head has been required to have a large number of ejection orifices arranged in high density. In order to reduce unevenness in printing to achieve high image quality, smaller variation in ejection properties of the ejection orifices is required. However, there is more difficulty in manufacturing all the ejection orifices without variation in the ejection properties as the number of ejection orifices increases. Thus, there arise problems such as a rise in manufacturing cost and degradation of a yield.
In order to deal with such problems, in Japanese Patent Application Laid-Open No. 2010-42511, there is disclosed a technology of driving a liquid ejection head with use of different drive waveforms for respective ejection orifices, to thereby attain uniform ejection properties of the ejection orifices even when the ejection orifices have different ejection properties. According to this technology, a driver integrated circuit (IC) configured to drive the liquid ejection head includes a storage section configured to store a plurality of waveform patterns and a selector configured to select one waveform pattern from the plurality of waveform patterns for each ejection orifice. The driver IC further includes a digital/analog (D/A) conversion circuit and a buffer amplifier. With this configuration, an ejection amount is corrected for each ejection orifice, to thereby reduce the difference in ejection properties.
However, in the technology disclosed in Japanese Patent Application Laid-Open No. 2010-42511, a large number of memories and logic circuits are required, and hence there is a problem in that a substrate area of the driver IC increases to cause an increase in the cost for manufacturing the liquid ejection head. In particular, in a case where an energy-generating element requiring a high-voltage drive waveform such as a piezoelectric element made of PZT is used, high-voltage processing is used. A driver IC for high voltage is higher in manufacturing cost as compared to an IC which is manufactured through typical complementary metal oxide semiconductor (CMOS) processing for a logic circuit. Further, refinement of the driver IC for high voltage is difficult. Thus, an area of the driver IC becomes larger relative to a circuit scale, with the result that the manufacturing cost is increased. Further, as the number of ejection orifices increases, the number of driver ICs to be used also increases, with the result that the manufacturing cost for the liquid ejection head increases accordingly.